JPH03172822A - Liquid crystal element - Google Patents

Abstract

PURPOSE:To improve the display quality concerning the generation of the flickering over the entire part of a screen, after-images, contrast, etc., and to improve high-speed responsiveness by forming a layer having a prescribed gradient with a transparent electrode surface on the outside of picture elements of at least one side face of at least one transparent electrode. CONSTITUTION:The liquid crystal element which has a smectic liquid crystal having a ferroelectric property and the transparent electrodes sandwiching the smectic liquid crystal is formed with the layer 16 having the gradient thetawith the transparent electrodes 12 surface on the outside of the picture elements of at least one side face of at least one transparent electrode. The flickering is suppressed under multiplexing driving and the generation of the domain attenuating with writing time or fluctuating in magnitude is prevented and the flickering is greatly improved by this layer 16 is formed. The gradient to the transparent electrode 12 surface is preferably <=30 deg.. Thus, the display quality, such as flickering, after-image and contrast, is improved and the liquid crystal display element which is extremely high in response speed is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a liquid crystal display element using a strong N-electroconductive smectic liquid crystal, and in particular to a smectic liquid crystal that improves the occurrence of flickering and afterimages and the contrast ratio during multiplex puff drive. It relates to display elements.

[Prior Art] A type of display element that uses the refractive index anisotropy of liquid crystal molecules to control transmitted light in combination with a polarizing element is manufactured by C1ark and Lagerwal.
l) (U.S. Pat. No. 4,367,924).
This liquid crystal generally has a chiral smectic C phase (SmC") or H phase (SmH") in a specific temperature range, and in this state, it responds to an applied electric field. 1st in response
It has the property of being in one of the optically stable state and the second optically stable state and maintaining that state when no electric field is applied, that is, it has bistability, and it also responds rapidly to changes in the electric field. Therefore, it is expected to be widely used as a high-speed and memory-type display element.

The aforementioned smectic liquid crystal element incorporates a matrix electrode composed of a scanning electrode and a signal electrode, a scanning signal is sequentially applied to the scanning electrode, and an information signal is applied to the signal electrode in synchronization with the scanning signal. Ru. When applying this multiplexing drive to a smectic liquid crystal element, when a refresh drive is used in which a scanning signal is repeatedly applied to the scanning electrodes and periodically applied, flickering occurs on the display screen (because the brightness of the entire screen changes periodically). There was a problem that caused flickering (flickering).

[Problems to be Solved by the Invention] An object of the present invention is to provide a novel liquid crystal element that solves the problems of conventional liquid crystal display elements as described above.

Another object of the present invention is to provide a liquid crystal display element with high-speed response.

[Means and Effects for Solving the Problems] It is an object of the present invention to provide a liquid crystal display element having a smectic liquid crystal having ferroelectricity and transparent electrodes sandwiching the smectic liquid crystal and facing each other. A liquid crystal display element that is achieved by forming a layer with a predetermined slope with respect to the transparent electrode surface outside the pixel on at least one side of the electrode, thereby improving display quality such as flickering, afterimages, and contrast. is provided.

The chiral smectic C phase (S
m C”) % H phase (SmH”), F phase (SmF”
), I phase (Sml”), J phase (SmJ”), G phase (
SmG'') or monophase (SmK'') liquid crystals are suitable. Tweet about this strongly charged liquid crystal is a″LE JOUR
NAL DE PHYSIQUE LETTER5”3
6 (L-69) 1975. rFerroel
etricLiquid Crystals J
“Applied Physics Letter
s 36 (11) 1980 rsubmi
cr.

5econd BIstable Electroop
tic 5w1tchin8inLiquid Cry
stals J; “Solid State Physics” 16 (141) 1
981r Liquid Crystal" and the like, and in the present invention, the strong electrostatic liquid crystal disclosed in these documents can be used.

Figure 1 schematically depicts an example of a ferroelectric liquid crystal cell. 21 and 21' are I n20. ．． A substrate (glass plate) coated with a transparent electrode made of a thin film of 5n02 or ITO (Indium-TinOxide), between which a liquid crystal molecular layer 22 is oriented perpendicular to the glass surface. S
A chiral smectic phase liquid crystal such as mI" Sm01 is sealed. The thick line 23 represents a liquid crystal molecule, and this liquid crystal molecule 23 has a dipole moment (P±) 24 in a direction perpendicular to the molecule. When a voltage higher than a certain threshold is applied between the electrodes on the substrates 21 and 21', the helical structure of the liquid crystal molecules 23 is unraveled so that all the dipole moments (P) 24 are oriented in the direction of the electric field. , the liquid crystal molecules 23 can change the orientation direction.The liquid crystal molecules 23 have an elongated shape and exhibit refractive index anisotropy in the major axis direction and the minor axis direction. It is easily understood that by placing crossed nicol polarizers, a liquid crystal optical modulation element whose optical characteristics change depending on the polarity of voltage application is obtained.

The liquid crystal cell preferably used in the present invention can be made sufficiently thin (for example, 10 μm or less).As the liquid crystal layer becomes thinner, an electric field is applied as shown in FIG. The helical structure of the liquid crystal molecules is uncoiled even in the non-helical state, and becomes a non-helical structure, and the dipole moment P or P' is either upward (arrow 34) or downward (arrow 34'). When an electric field E or E' with a different polarity above a certain threshold value is applied to such a cell by a voltage applying means (not shown) as shown in FIG. 2, the dipole moment changes to the electric field vector of the electric field E or E'. Correspondingly, the liquid crystal molecules change their orientation upwards 34 or downwards 34', and accordingly the liquid crystal molecules enter the first stable state 3.
3 or the second stable state 33'.

As mentioned earlier, there are two advantages to using such a ferroelectric liquid crystal cell.

The first is that the response speed is extremely fast. The second is that the alignment of liquid crystal molecules has bistability. To further explain the second point, for example with reference to FIG.
When the voltage is applied, the liquid crystal molecules are aligned in a first stable state 33, and this state remains stable even when the electric field is turned off. When an electric field E' in the opposite direction is applied, the liquid crystal molecules are oriented to a second stable state 33' and change their orientation, but they remain in this state even after the electric field is removed. Further, as long as the applied electric field E does not exceed a certain threshold value, each orientation state is maintained. Such fast response speed and
In order to effectively realize bistability, it is preferable that the cell be as thin as possible.

Generally 0.5 μm to 20 μm 1 Especially 1 μm to 5 μm
is suitable. A liquid crystal electro-optical device having a matrix electrode structure using this type of ferroelectric liquid crystal has been proposed, for example, by Clark and Ragabal in US Pat. No. 4,367,924.

The present inventors further investigated the arrangement state of molecules of ferroelectric smectic liquid crystal and the optimization of liquid crystal elements using a combination of polarizer analyzer. However, depending on the substrate processing method, the liquid crystal material, the thickness of the liquid crystal cell, etc., different forms of alignment may occur, and there may be domains on the side of the pixel that attenuate or change in size with writing time. In some cases, it has been found that said domains are responsible for flickering, afterimages and contrast reduction.

Then, they discovered that by forming a layer on the side of the pixel outside the pixel that has a slope with respect to the transparent electrode surface, it is possible to improve the occurrence of the domains, and it is possible to improve flickering, afterimages, and contrast. Ta.

FIG. 3 is a perspective view showing an embodiment of a substrate used in the liquid crystal display element of the present invention. In the figure, 11 is a substrate made of glass or plastic, 12 is a transparent electrode made of ITO, etc., and 13 is
14 is a low-resistance connection line formed of a metal such as aluminum, chromium, molybdenum, or an alloy thereof, 14 is a stepped portion extending in one direction, and 15 is a ridgeline thereof.

The number of transparent electrodes 12 is 300 to 5000, preferably 50.
The film thickness is 0 to 2000, and the low resistance connection line 13 is provided with a thickness of 300 to 5000, preferably 500.
It is provided with a thickness of 3,000 to 3,000 people.

Furthermore, in the present invention, there is no need to prevent short circuits between the upper and lower electrodes on the substrate 11! A film (not shown) can be provided, and an alignment film can be further provided on the insulating film. At this time, the insulating film is made of Sin.

A polyvinyl alcohol film, a polyimide film, a polyamide film, a polyester film, a polyamide-imide film, a polyester-imide film, etc. can be used as the alignment film.

FIG. 4(A) shows an embodiment in which two substrates shown in FIG. 3 are prepared. In this liquid crystal display element, as shown in FIG.
Two substrates 11a and 11b shown in FIG. 0 are arranged facing each other at points Aa and Ab, and points Ba and Bb.
4 and Rb4 are glaze orientation processing axes such as rubbing processing axes applied to each substrate. By arranging the two substrates 11a and llb facing each other as described above, the low resistance connection line 1
3a and the transparent electrode 12a are each connected to a low resistance connection line 13.
b and the transparent electrode 12b, forming a pixel P4 shown in FIG. 4(B).

In the pixel P4 shown in FIG. 4(B), the -axis alignment processing axis Ra
4 is set in a direction perpendicular to the low resistance connection line 13a corresponding to the linear protrusion existing in the pixel P4, and is oriented toward the low resistance connection line 13a.

In the liquid crystal element in which the pixel P4 shown in FIGS. 4(A) and 4(B) is formed, a plurality of pairs of hairpin defects 14 and lightning defects 15 are formed, and a plurality of pairs of hairpin defects 14 and lightning defects are formed. The portions 15 are regularly generated parallel to the -axis alignment processing axis Ra4, and among the hairpin defect portions 14 and the lightning defect portions 15, the lightning defect portions 15 are more equivalent to linear protrusions than the hairpin defect portions 14. This occurs near the low resistance connection line 13a.

The aforementioned hairpin defect portion 14 and lightning defect portion 15 occur in pairs, and are caused by bead spacers or fiber spacers dispersed within the cell. Therefore, the number of hairpin defect portions 14 and lightning defect portions 15 that form a pair is correlated with the number of bead spacers and fiber spacers dispersed. In addition, even if there is no bead spacer or fiber spacer, it can also be caused by lightly pressing the cell with a finger.

FIGS. 7(A) to 7(C) are diagrams schematically sketching aspects of hairpin defects and lightning defects. Figure 7 (A
) represents a hairpin defect 71 and a lightning defect 72 caused by the bead spacer. FIG. 7(B) shows a defective state in which the defect is further grown by gently pressing the cell with the defective state shown in FIG. 7(A) with a finger, and FIG. 7(C) shows the defective state. This reveals how the situation has grown even further.

As clarified in FIGS. 7(A) to (C), the hairpin defect 71 and the lightning defect 72 are generated in pairs, and the surrounding domain (chiral smectic C2 domain 74) and optical state (for example, transparent (2) The line width W1 of the hairpin defect 71 is larger than the line width W2 of the lightning defect 72, and the line width W of the hairpin defect 71 is generally 2 to 10 μm.
The line width W of the lightning defect 72 is 2 μm or less, and a chiral smectic C phase is formed in which the domain 73 surrounded by the hairpin defect 71 and the lightning defect 72 has an orientation different from that of the surrounding domain 74; The respective domains can be defined as chiral smectic CI domain 73 and chiral smectic C, domain, and these two different domains generally exhibit different optical states (transmittance) and can be distinguished microscopically.

In addition, the above-mentioned hairpin defect and lightning defect are discussed in Proceedings of the October 1988 LCD Symposium, P, 114-115.
``Decision regarding the structure of 5SFLC state by r microspectroscopy''.

The present inventors performed writing using the multiplexing method shown in FIG. 5 at a frame frequency of 1 to the liquid crystal element forming the pixel P4 shown in FIGS.
When the test was performed at 0 Hz, it was found that flickering, which is a periodic change in screen brightness, was observed when the pixels were in a dark state (black display state). In addition, when the above-mentioned liquid crystal element was observed under a microscope under multiplex leg drive, it was found that the threshold voltage 1
When a voltage of 1±V, 1 exceeding ±Vthl is applied to make the pixel P4 in a dark state (black display state), the low resistance connection line 13a
In the area on the side A where there is no inversion part 16 (domain that decreases or changes in size with writing time) is formed every frame period, and the occurrence of such an inversion part 16 is believed to be the cause of the above-mentioned flickering. found. Note that FIG. 5 shows the waveform of the voltage applied to the pixel P4 in time series.

Furthermore, when the pixel P4 is in a bright state (white display state), an inverted portion 17 (a domain that decreases or changes in size with writing time) is formed on the side surface of the hairpin defect every frame period, but the flickering described above I couldn't see it.

FIG. 4 is a sketch of a micrograph at 200x magnification. Various types of chiral smectic liquid crystals can be used in the present invention. For example, U.S. Pat. No. 4,561,726, U.S. Pat. No. 4,614,600
Chiral smectic liquid crystals described in US Pat. No. 9, US Pat. No. 4,589,996, US Pat. No. 4,596,867, US Pat. No. 4,613,209, US Pat. No. 4,615,586, etc. can be used.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

FIGS. 6(A) and 6(B) show an embodiment of the liquid crystal display element of the present invention. FIG. 6(A) is a plan view of the liquid crystal element of the present invention, and FIG. 6(B) is a cross-sectional view taken along the line AA'.

In the cell structure 600 shown in FIG. 6, a pair of substrates 601 and 601' made of glass plates, plastic plates, etc. are held at a predetermined distance by a spacer 604, and an adhesive 606 is used to seal the pair of substrates. It has a bonded cell structure, and furthermore, on the substrate 601, an electrode group (for example, a scanning voltage application electrode group of a matrix electrode structure) consisting of a plurality of transparent electrodes 602 is arranged in a predetermined pattern such as a strip pattern. formed of a pattern. On the substrate 601', an electrode group (for example, a signal voltage application electrode group of the matrix electrode structure) is formed, which is made up of a plurality of transparent electrodes 602' intersecting with the transparent electrode 602 described above. The transparent electrodes 602 and 602' each have a low resistance connecting wire 6.
10.610' is provided.

The substrate 601' provided with such a transparent electrode 602' may contain, for example, silicon oxide, silicon dioxide, aluminum oxide, zirconia, magnesium fluoride, cerium oxide, cerium fluoride, silicon nitride, silicon carbide, boron nitride. Inorganic insulating materials such as objects, polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyparaxylerin, polyester, polycarbonate,
polyvinyl acetal, polyvinyl chloride, polyamide,
The alignment film 605 may be formed by forming a film using an organic insulating material such as polystyrene, cellulose resin, melamine resin, area resin, or acrylic resin.

The alignment film 605 is obtained by forming a film of an inorganic insulating material or an organic insulating material as described above, and then rubbing the surface in one direction with velvet, cloth, or paper.

In another preferred embodiment of the present invention, alignment film 605 can be obtained by depositing an inorganic insulating material such as SiO or 5i02 on substrate 601' by oblique vapor deposition.

In another specific example, after forming a film of the above-mentioned inorganic insulating material or organic insulating material on the surface of the substrate 601' made of glass or plastic or on the substrate 601',
By etching the surface of the film by an oblique etching method, an orientation control effect can be imparted to the surface.

The above-mentioned alignment film 605 preferably functions as an insulating film at the same time, and for this reason, the thickness of the alignment film 605 is generally 100 to 1 μm, preferably 500 to 50 μm.
It can be set to a range of 00 people. This insulating film is
It also has the advantage of being able to prevent the generation of current caused by impurities etc. contained in a small amount in the liquid crystal layer 603, so that even if the operation is repeated, the liquid crystal compound will not deteriorate.

Further, in the liquid crystal element of the present invention, a film similar to the above-described alignment film 605 can be provided on the other substrate 601.

This cell structure 600 has a chiral smectic liquid crystal 603 in which a plurality of layers organized by a plurality of molecules are formed adjacently, and the film thickness of the chiral smectic liquid crystal 603 forms a unique helical structure in a bulk state. set thin enough to suppress This point is detailed in US Pat. No. 4,367,924.

Such a cell structure 600 includes substrates 601 and 601'.
Polarizers 607 and 608 in a crossed Nicol state or a parallel Nicol state are arranged on both sides of the electrode, respectively, and optical modulation occurs when a voltage is applied between the electrodes 602 and 602'.

Factor 1: Two 1.1 mm thick glass plates were prepared, and striped ITO electrodes were formed on each glass plate. A metal wiring made of molybdenum was formed on this substrate to a thickness of 1000 mm, spanning between the ITO electrode and the pixel, like the low resistance connection line 13 in FIG. Furthermore, as a short-circuit prevention layer for the upper and lower electrodes, a film of 500% of Sin was coated using the batter method.
Formed a person.

A 0.1% aminosilane IPA (isopropyl alcohol) solution was applied thereon for 15 seconds using a spinner with a rotation speed of 2000 rpm, and after baking at 150°C, a 2% solution of polyimide forming liquid 5P510 (manufactured by Toshi Co., Ltd.) (NMP: n-butyl cellosolve) was applied. =2:1) was applied for 30 seconds using a spinner with a rotation speed of 300 rpm. After film formation, 300℃ for about 1 hour
A polyimide alignment film was formed by performing a heating and baking treatment.

The film thickness of this coating was 200 polyimide films.

Next, on one glass (first substrate), a rubbing treatment was applied to the fired polyimide film in the direction of Rb4 shown in FIG. 4(A). On the other glass plate (second substrate), the fired polyimide film was subjected to rubbing treatment in the direction of Ra4 shown in FIG. 4(A).

After that, after scattering alumina beads with an average particle size of about 1.5 μm on one glass plate, each rubbing axis and its direction become parallel rubbing as shown in Fig. 4 (A) and (B). A cell was created by gluing one glass plate and the other glass plate together.

The cell thickness of this cell was measured using a Berek phase plate (measurement based on phase difference) and was found to be approximately 1.5 μm. Into this cell, "C5-1014J (product name)" manufactured by Chisso Corporation was injected under vacuum injected by Toro Minister, and then 0.
Orientation could be achieved by slow cooling to 60°C at a rate of 5°C/h. Subsequent experiments were conducted at 25°C.

In addition, the phase change of rCS-1014J mentioned above was as follows.

-21t 54.4℃ 69.1℃ 8
0.5℃Cry, -*SmC' →Sm^
-+Ch →ls.

However, SmA indicates smectic A phase, ch indicates cholesteric phase, and Iso indicates isotonic phase.

When this cell was observed under crossed nicols, monodomains were obtained that formed a chiral smectic C phase with a -like, defect-free, non-helical structure.

In addition, this liquid crystal element was kept at 60°C, brought into an SmA orientation state, and observed under a polarizing microscope using an orthogonal crossed nifle.
The direction of the layer was measured using the fact that liquid crystal molecules are aligned perpendicularly to the layer under mA conditions.

As a result, it was confirmed that the rubbing direction was perpendicular to the rubbing direction.

This liquid crystal element was multiplexed driven using the driving method shown in FIG.

This is a method in which a bright state and a dark state can be written in one frame, and it is a 3.DELTA.th driving method that requires a one line scanning period of 3.DELTA.ths for a writing pulse width .DELTA.T.

FIG. 5(A) shows the scanning signal applied to the n-th scanning line Sn, and FIG. 5(B) shows the information signal applied to a certain information line ■: white → white → white → white → black → white. →White→White information signal. FIG. 5(C) shows a composite waveform applied to the intersection of the scanning line Sn and the information line I.

When writing was performed using the multiplexing method shown in FIG. 5 at a frame frequency of 10) 1z on the liquid crystal element in which the pixel P4 shown in FIGS. 4(A) and (B) described above was formed, the pixel In the dark state (black display state), flickering was observed in which the brightness of the screen periodically changed. In addition, when the above-mentioned liquid crystal element was observed under a microscope while being driven by a multiplex puffer, it was found that a voltage of 1±vat exceeding the threshold voltage of 1±V th l was applied to bring pixel P4 into a dark state (black display state). In this case, an inversion part 16 (a domain whose magnitude decreases or changes with writing time) is formed in the region of side A where there is no low resistance connection line 13a every frame period, and the occurrence of such an inversion part 16 is caused by the above-mentioned problem. It turned out that it was caused by flickering. Note that FIG. 5 shows the waveform of the voltage applied to the pixel P4 in time series.

Furthermore, when the pixel P4 is in a bright state (white display state), an inverted portion 17 (a domain that decreases or changes in size with writing time) is formed on the side surface of the hairpin defect every frame period. No flickering was observed.

Therefore, in FIG. 3, a layer having a slope with respect to the surface of the transparent electrode was formed by laminating and etching Sin on the side surface of the transparent electrode on the side where the low resistance connection line was not provided. 8th
Figure (A) shows a substrate on which a graded layer 16 has been formed. At this time, when the cross section of the substrate was observed by SEM, it was found that the slope θ of the layer 16 having a slope with respect to the transparent electrode was about 30° when the transparent electrode surface was used as a reference.

Similarly to the above, writing is performed using the multiplexing method shown in FIG. 5 at a frame frequency of 10 on the liquid crystal element in which the pixel P4 shown in FIGS. 4(A) and 8(A) is formed.
When conducted at Hz, no flickering, which is caused by periodic changes in screen brightness, was observed when the pixels were in a dark state (black display state). FIG. 8(C) shows a state in which the above-mentioned liquid crystal element was observed under a microscope while being driven by a multiplex puffer. When a voltage 1±val exceeding the threshold voltage 1±V th I is applied to bring the pixel P4 into a dark state (black display state), the inversion portion 16 (writing time (domains that decrease or vary in size) have not occurred. Therefore, it was found that there was no flickering. Note that FIG. 5 shows the waveform of the voltage applied to the pixel P4 in time series.

Furthermore, when pixel P4 is in a bright state (white display state), an inverted portion 17 (a domain that decreases or changes in size with writing time) is formed on the side surface of the hairpin defect every frame period, but no flickering is observed. There wasn't.

From the above, as shown in FIG. 8, by forming a layer on the side surface of the pixel that has a slope with respect to the transparent electrode surface, flickering can be suppressed under multi-bleaching puffer drive. That is, it was possible to prevent the occurrence of domains whose attenuation or size fluctuates with writing time, and flickering was significantly improved.

Furthermore, when the afterimage time and contrast ratio were compared with and without the gradient layer, the results are shown in Table 1 below.

That is, according to the present invention, flickering, afterimage time, and contrast ratio can be significantly improved.

In addition, by adjusting the etching rate of Sin, the slope θ of the layer 16 having a slope with respect to the transparent electrode is set to 45°, 60°,
900, it was found that when θ=30° was exceeded, an inversion portion was formed in the region of the side A of the pixel where there is no low resistance connection 1ja 13 a.

From the above, it can be seen that the slope θ of the layer having a slope with respect to the transparent electrode is preferably 30' or less.

A liquid crystal cell was prepared in exactly the same manner as in Example 1, except that the direction of the lamp slabbing treatment was oriented as shown in FIG. 9(A), and the same tests as in Example 1 were conducted.

At this point, as shown in FIG. 9(B), during driving, a reverse inversion domain (inversion portion 16) in the opposite direction to the pixel writing direction was generated from the side B where the low resistance connection line 13a is located.

Furthermore, when observing the orientation state within the pixel, Fig. 9(B)
As shown in , there are hairpin defects and lightning defects caused by alumina beads, and a reverse inversion domain (inversion part 17) in the opposite direction to the pixel writing direction occurs on the side of the lightning defect, causing flickering. I could see it.

Therefore, by adjusting the etching rate of the low-resistance connection line (the wiring part does not transmit light and does not become a pixel because a metal thin film such as An or MO is used), the low-resistance connection line was created as shown in Figure 10. A gradient was formed on the side surface of the transparent electrode.

In this case as well, exactly the same effect as in Example 1 was obtained. That is,
As shown in FIG. 10(C), no reverse inversion domain was generated from side B where the low resistance connection line 13a is located, and flickering, afterimage, and contrast were improved.

In Examples 1 and 2 above, the etched surface of the layer formed on the side surface of the transparent electrode that is sloped with respect to the transparent electrode surface is not necessarily flat, and as shown in FIGS. There were various shapes as shown, but all of them had exactly the same effect as Example 1.

A cell similar to that in Example 1 was prepared and tested, except that the materials listed in Table 2 below were used as the LL axis alignment film and liquid crystal material, and the results were the same as in Example 1. there were.

In Table 2, rsElooJ, rsE4110J and rLP
64J is a resin liquid for forming a polyimide film.

[Effects of the Invention] As explained above, according to the present invention, a layer having a predetermined slope with respect to the transparent electrode surface is formed outside the pixel on at least one side of at least one transparent electrode. This provides a liquid crystal display element with improved display quality in terms of flicker, afterimage, contrast, etc. of the entire screen, and which has high-speed response.

[Brief explanation of the drawing]

1, 2, and 3 are perspective views of the substrates used in the present invention, FIG. 4(A) is a plan view of a pair of substrates used in the present invention, and FIG. 4CB) is a Figure 4 (A) is a plan view of the pixel, Figures 5 (A) to (C) are waveform diagrams of the driving voltage used in this example, and Figure 6 (A) is the cell used in the present invention. Fig. 6 (CB) is a cross-sectional view taken along line AA' in Fig. 6 (A), and Fig. 7 (A) to (C) are explanatory diagrams schematically sketching hairpin defects and lightning defects. , FIG. 8(A) is
FIG. 8(B) is a sectional view of the substrate of FIG. 8(A); FIG. 8(C) is a perspective view of a substrate of a liquid crystal display element according to an embodiment of the present invention; 9(A) is a plan view of another pair of substrates used in another embodiment of the present invention; FIG. 9(B) is a plan view of a pixel of a liquid crystal display element using the substrate of FIG. 9(A) is a plan view of a pixel, FIG. 10(A) is a perspective view of a substrate of a liquid crystal display element according to another embodiment of the present invention, and FIG. 10(B) is a plan view of a pixel in FIG. 10(A). 10(C) is a plan view of a pixel of a liquid crystal display element using the substrate of FIG. 10(A), and FIG. 11 is a cross-sectional view of the substrate of FIG. FIG. θ: slope.

Claims (2)

[Claims] (1) In a liquid crystal element having a smectic liquid crystal having ferroelectricity and transparent electrodes sandwiching the smectic liquid crystal and facing each other, at least one of the transparent electrodes is formed outside the pixel on at least one side of the transparent electrode. A liquid crystal element comprising a layer having a predetermined gradient with respect to a transparent electrode surface. (2) The liquid crystal element according to claim 1, wherein the predetermined slope is a slope of 30 degrees or less with respect to the transparent electrode surface.